Antibody depletion for the treatment of crossmatch-positive pediatric heart transplant recipients

Abstract

Sensitization to HLA is a risk factor for adverse outcomes after heart transplantation. Requiring a negative prospective CM results in longer waiting times and increased waitlist mortality. We report outcomes in a cohort of sensitized children who underwent transplant despite a positive CDC CM+ using a protocol of antibody depletion at time of transplant, followed by serial IVIG administration. All patients <21 yrs old who underwent heart transplantation at Boston Children's Hospital from 1/1998 to 1/2011 were included. We compared freedom from allograft loss, allograft rejection, and serious infection between CM+ and CM- recipients. Of 134 patients in the cohort, 33 (25%) were sensitized prior to transplantation and 12 (9%) received a CM+ heart transplant. Serious infection in the first post-transplant year was more prevalent in the CM+ patients compared with CM- patients (50% vs. 16%; p = 0.005), as was HD-AMR (50% vs. 2%; p < 0.001). There was no difference in freedom from allograft loss or any rejection. At our center, children transplanted despite a positive CM had acceptable allograft survival and risk of any rejection, but a higher risk of HD-AMR and serious infection.

Keywords: anti-HLA antibody; antibody-mediated rejection; infectious risk; outcome; pediatric heart transplantation; plasmapheresis.

Figure 1

Kaplan-Meier freedom from allograft loss after pediatric heart transplantation stratified by CDC crossmatch result. There was no significant difference in allograft loss (P=0.2).

Figure 2

Kaplan-Meier freedom from rejection (ISHLT Grade ≥ 3A/2R cellular rejection or antibody mediated rejection) after pediatric heart transplantation stratified by CDC crossmatch result. There was no significant difference in the time to first rejection episode (P=0.3).

Figure 3

Kaplan-Meier freedom from serious infection after pediatric heart transplantation stratified by CDC crossmatch result. Patients with a positive CDC crossmatch were significantly more likely to be treated for infection (P<0.001).